[IronPython] PyPy and GenCLI

[Michael Foord]

Hello all,

I've read the PyPy EU report on the CLI backend. Most of it is 
experimental and interesting, but hard to see how it is directly 
immediately useful.

If I understand the GenCLI backend correctly though, it may be of 
interest to this list.

IIUC, GenCLI takes RPython code and compiles to IL - with native .NET 
classes for classes defined in RPython.

In PyPy, this is used to translate PyPy itself to provide a Python 
interpreter on top of .NET (unlike IronPython which is a compiler).

(RPython is a static subset of Python - all RPython code is valid Python 
code, but not vice-versa.)

If I'm right, then RPython could be used to compile native .NET 
assemblies, which of course could be used from IronPython. This may be a 
preferable optimisation route than dropping down into C# where extra 
speed is needed.

When benchmarking performance of GenCLI (and PyPy), this is the figures 
they came up with for an implementation of the classical Martin 
Richards’s benchmark :

Implementation Result
richards-c# 7.093
richards-gencli 13.312
CPython richards.py 1139.632
IronPython richards.py 1751.246
pypy-cli richards.py (built-in) 5952.501
pypy-cli richards.py 12010.541

As you can see, gen-cli code is not much slower than C#.

All the best,

Michael Foord
http://www.voidspace.org.uk/ironpython/